In recent years, progress has been made in the research and development of organic EL panels. The organic EL panels are display panels that rely on the phenomenon of electroluminescence of an organic material. A matrix of R (red), G (green), and B (blue) subpixels is arranged on a substrate of such an organic EL panel.
It is important to improve light-extraction efficiency of the R, G, and B subpixels, from the standpoint of reducing power consumption or increasing service life of the organic EL panel.
To this end, Patent Literature 1 proposes an art of increasing transmitted-light intensity of an organic light-emitting display device constituted of a reflective film, an interlayer insulation film, a first transparent electrode, a hole transport layer, an organic light-emitting layer, an electron injection layer, and a second transparent electrode that are layered on a substrate. Incident-light intensity is increased by using the phenomenon of interference between direct light that travels directly from the organic light-emitting layer toward the second transparent electrode and reflective light that reflects off the reflective film after being emitted from the organic light-emitting layer and then travels toward the second transparent electrode (paragraphs 0022-0024).